Linked Life Data

17949700

Source:http://linkedlifedata.com/resource/pubmed/id/17949700

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2007-11-5
pubmed:abstractText
Seasonally breeding animals undergo numerous physiological changes in response to changes in the length of the photoperiod. In most warm-weather breeding rodents, these changes result in reproductive quiescence during short photoperiods. It has been hypothesized that this change is mediated by changes in the activity of gonadotropin-releasing (GnRH) hormone neurons of the hypothalamus. This study was designed to test whether there are changes in the releasable pool of GnRH in the hypothalamus in response to changes in photoperiod, the presence of gonadal steroids, or the responsiveness of the individual animal to photoperiodic changes. Male deer mice (Peromyscus maniculatus) were maintained on long or short day photoperiod and either left intact, castrated, or castrated with testosterone replacement. KCl-evoked GnRH release was measured from hypothalamic explants from each animal and compared between long and short days, between castrated, intact, and castrated with testosterone replacement animals, and between animals that did or did not show gonadal regression in response to short day treatment. There was a significant decline in evoked release of GnRH in short day housed animals when comparing photoperiod responsive mice to nonresponsive mice. In addition, both reproductively nonresponsive and long day-housed mice release less GnRH following castration than their intact counterparts. When castrated long day-housed mice were provided with long day levels of testosterone, evoked GnRH release was restored to intact levels. Taken together, the results of this study suggest that variation in testicular response to short days is most likely due to differences in the release of GnRH from the hypothalamus.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
1180
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20-8
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Short photoperiod and testosterone-induced modification of GnRH release from the hypothalamus of Peromyscus maniculatus.
pubmed:affiliation
Department of Biological Sciences, Kent State University, Kent, OH 44242, USA. emintz@kent.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't